Extended Defects in Deformed Rutile

High‐resolution electron microscopy is used to study the fine structure of extended defects occurring within specimens of mechanically deformed and reduced rutiles (≈ TiO_1.9966). These reveal the strong dependence of precipitation phenomena on the precise details of specimen cooling history and on the direction of the compression axis (i.e. [110] or 〈111〉). It is concluded that dislocation dissociation mechanisms play a relatively minor role in deformation mechanisms in reduced rutiles. The fact that applied stress favors occurrence of clusters of small linear defects within the nonstoichiometric phase TiO_2−x, at the temperature of deformation, seems necessary to explain the observed defect structures. Thus it appears that plastic deformation of rutile may be achieved directly by the precipitation of extended defects, rather than by traditional dislocation mechanisms.